The present invention relates to a gas discharge display system utilizing panels constructed to operate on matrix discharge logic principles as disclosed and claimed in Schermerhorn patent application Ser. No. 372,730, now U.S. Pat. No. 3,925,703, issued Dec. 9, 1975, Schermerhorn patent application Ser. No. 372,540, abandoned, and Schermerhorn patent application Ser. No. 372,543, now U.S. Pat. No. 3,833,832, all filed June 22, 1973. As disclosed in the above-identified patent applications, gas discharge panels constructed to operate on matrix discharge logic principles are capable of accomplishing a large amount of multiplexing internally of the panel thereby reducing the number of external connections to such panels. This is done by taking advantage of the fact that if a single electrode or conductor on a panel is replaced by two closely spaced electrodes, as disclosed in Schermerhorn U.S. Pat. No. 3,846,656 (application Ser. No. 372,541) assigned to the assignee hereof and incorporated herein by reference in its entirety, the resultant cell discharges in such electrode systems tend to merge across the electrode space so that if one side of a cell or the other is erased, the one "on" side will re-ignite the side that has been erased. Thus, since a complete cell erasure can only be accomplished by erasing both halves of a cell, a convenient multiplexing scheme can be established taking advantage of this phenomena. One way in which panels can be written for display purposes in such a system is disclosed in Schermerhorn U.S. Pat. No. 3,840,779 entitled "Circuits for Driving and Addressing Gas Discharge Panels by Inversion Techniques". According to this patent, cell inversion is used to erase the cells that are ON and then re-invert the entire panel. Thus, "writing" in such panels occurs by erasing the complementary state. While this approach of utilizing the discharge logic concept is effective for relatively larger displays, its expense is relatively higher for smaller and medium size displays.
Accordingly, it is an objective of the present invention to provide an improved method and apparatus for entering information to a gaseous discharge display panel constructed to operate on matrix discharge logic principles.
According to the invention, a selected block (or matrix) of information sites or information display points on the panel, such as for one character, are written in bulk, e.g. simultaneously. This method takes advantage of the groupings which occur for multiplexing and the ability of a half ON cell to ignite the OFF half. As disclosed in Schermerhorn U.S. Pat. No. 3,846,656, a typical discharge logic multiplexing scheme has groupings of adjacent lines (ALG) bussed or connected together interlaced with groupings of dispersed lines (DLG) connected by means of some type of crossover network, which may be external or internal of the panel. As thus constructed, if a write pulse is applied to one adjacent line grouping on one axis of a panel and to an adjacent line grouping on the other axis, all cells or sites at sites common to the intersection of the ALG's will be ignited, hence causing a matrix of cells to be bulk written.
The above and other objects, advantages and features of the invention will become more apparent from the following specification taken in conjunction with the accompanying drawings wherein: